86 Yoda Turbo Clanking Noise

Sons 86 yoda while driving made all knid of noise he pulled over and the oil return line had come off and oiled up the hwy. He put the line back on added oil the ndrove home the truck ran fine for 2 weeks and the other day while on the way to work it started making ssame noise he said he shut engine down and rechecked the return line it was on and there was plenty of oil in the pan ,the presure gauge on his truck said it had oil presure.My question is could the oil pump on the front cover gone bad ? If not what could be causeing noise?He hates to think of having the motor re-built.Any help as always is very thankful you dont even relize how much .Thanks in advance Mitch

the head might have died from running with no oil?